Field of the Disclosure
Embodiments of the present invention relate to a display apparatus, and more particularly, to an apparatus for converting data which is capable of enhancing sharpness without deterioration of picture quality, and a display apparatus using the same.
Discussion of the Related Art
With the development of multi-media, a display apparatus such as television is becoming increasingly important. Thus, various display apparatus are widely used, for example, liquid crystal display apparatus, plasma display apparatus, organic light emitting display apparatus, and etc.
Generally, a display apparatus may include a plurality of unit pixels in accordance with a preset resolution, wherein each unit pixel may include red (R), green (G) and blue (B) sub-pixels.
In order to improve luminance for each unit pixel, recently, a display apparatus with a white (W) sub-pixel additionally provided to each unit pixel has been developed and utilized. This display apparatus converts 3-color input data of red, green and blue colors into 4-color data of red, green, blue and white colors, and displays the 4-color data.
In order to generate a clear image with good picture quality in the display apparatus with the white (W) sub-pixel, a sharpness enhancement technique is applied to emphasize an edge portion of an image. In this case, the display apparatus adopting the sharpness enhancement technique may include an apparatus for converting data which enhances sharpness for input image on the basis of 3-color input data, and converts the 3-color input data with the enhanced sharpness into 4-color data.
A related art apparatus for converting data converts 3-color input data (RGB) for each unit pixel into luminance components (Y) and chrominance components (CbCr) enhances sharpness of edge portion by analyzing the luminance components (Y) for each unit pixel and correcting luminance components (Y) of edge portion of input image, converts the luminance components (Y′) and chrominance components (CbCr) into 3-color data (R′G′B′), converts the 3-color data (R′G′B′) into RGBW 4-color data, and outputs the RGBW 4-color data.
However, the related art apparatus for converting data may have the following disadvantages.
First, since the change of luminance components (Y) in the edge portion of image makes the change of RGB 3-color data of the unit pixel, the change of sharpness becomes wide, and excessive sharpness enhancement may occur, which causes deterioration of picture quality. For example, if the sharpness correction process according to the related art is performed to image (a) of FIG. 1, a ringing artifact may be added to the image. That is, an edge portion of the image (a circumferential area of a black-colored letter) would look white, as shown in image (b) of FIG. 1, causing deterioration of picture quality.
Also, the related art apparatus for converting data needs the steps of converting the RGB 3-color data into the luminance components (Y) and re-converting the luminance components (Y) into the RGB 3-color data.